Research On Characteristics Of Jacket Platform Against Collision

Recent years, considering the decreasing amount of nature resource on the land, the recourse exploitation has invaded to the ocean; especially direction to the blue water has become necessary. However, for the offshore platforms which are the main structure used for the oil exploitation, the security of its building and using has accepted more and more attention from the public. Ship collision can always make some disasters, including structure damage, environment pollution and casualties. Therefore, to improve the resistibility of ship is of great importance, no matter what consider safety, economy and protecting environment.Collision happened between the ship and platform is a complicated nonlinear instantaneous process under huge impact load, which could finish in a very short time period (about 0.1s~1.0s), and the whole process ascribes to the nonlinear problem. Different from the collision happened on land, collision happened between the ship and platform belongs to the typical problem of Fluid-Structural Coupling. Moreover during the collision process, many factors can affect collision result such as the property of the ship, the level of the collision intensity, and the relative position, velocity and the location of the collided ship. Because of the whole things above, the research of the collision happened between the ship and platform become very complex and difficult, which need to use many basis theories such as fluid dynamics, inelastic mechanics, fracture mechanics and the structural reliability.At present, many research methods have been used for the analysis of collision happened between the ship and platform, including empirical method, simplified analytical method, experimental method, finite element method (FEM), and so on. And nonlinear finite element numerical simulation is one of the most effective methods among them. Now this method has been used in engineer work extensively.In this paper the finite element model of collision of ship and platforms was built to study the structures collision characteristics. By the research of collision simulations, we obtain the pictures about damage distortion depended time and the curve of relative between energy and distortion, crashworthiness and distortion.The paper discusses the influence of different quality; initial velocity and collision position to the characteristics of platform structure in collision, and estimate the max collision force formula by the different result; compute the influence on the collided platform, when the sea-ice surrounding the structure. At last get the process of sea-ice breaking and the result for the different sea-ice areas.